In very simplified terms, an accumulator of this type comprises a plurality of elements each consisting of a negative plate, a positive plate and separating means intercalated between these plates.
The production of an accumulator of high energy-to-weight ratio, which is very durable, presents a fundamental technical problem. Thus, in particular, it is necessary to find a means of improving the efficiency of the active materials whilst at the same time preventing them from swelling and preventing the positive material from shedding; it is also necessary to reduce the corrosion of the grids holding these active materials.
The separating means of the accumulator play a very important part in improving all the abovementioned factors. Numerous types of separating means comprising microporous separators have already been proposed.